Error Message

 WARNING: msgcnt mesg 128: V-2-128: number of links reached vx_maxlink for inode on filesystem

AIX has a Operating System limitation which restricts the number of links of an inode to 32K (MAXLINK). Therefore one cannot create sub-directories greater than 32K.

IBM suggested that VxFS could ignore the MAXLINK value to accommodate this requirement.  

VxFS uses an internal 32 bit link count and hence VxFS internal structures are capable of handling more than 32k sub-directories.  None of the VxFS commands use MAXLINK count hence there are no other dependencies. So a new tunable i.e. 'maxlink_enable' has been added to allow >32k sub-directories and removed limitation of 32K sub-directories This is implemented via a tunable.  

/opt/VRTSvxfs/sbin/vxtunefs can be used to set the maxlink_enable to 1.  

Once set for the system, it cannot be unset.   Please upgrade to following patch wihch include the enhancement  to set maxlink_enable 

sfha-aix-5.1SP1RP4 https://sort.Veritas.com/patch/detail/7886

sfha-aix71-5.1SP1PR1RP4 https://sort.Veritas.com/patch/detail/7887

Known Limitations with this fix: 

AIX Base command limitations: 

Since the value of MAXLINK can go only up to 32k, certain AIX commands that have the dependency on this value would fail to produce correct results. IBM has completed the analysis of such commands and following are expected to produce incorrect results when run with >32K directories. AIX commands /usr/bin/istat, /usr/bin/li, /usr/bin/ls and /usr/bin/find commands will report incorrect nlink count when there are >32k subdirectories. 

VxFS limitations :  

In case of CFS, ALL nodes of the cluster must run with same maxlink_enable value. 

Once this tunable is set then it cannot be disabled. By default it is disabled

Solution for version 6.2 and above

Starting with Storage Foundation 6.2 a new mount option 'maxlink' is available. This mount option can be used to turn the maxlink behaviour on or off. By default it is disabled at 6.2 but is enabled by default on later versions.

To enable maxlink at version 6.2:

To enable the maxlink option at mkfs time. For example:

To disable the maxlink option at mkfs time. For example:

To enable the maxlink option through the fsadm command on a mounted files system. For example:

To disable the maxlink option through the fsadm command on a mounted file system. For example:

See the mkfs_vxfs(1M) and fsadm_vxfs(1M) manual pages.

Applies To

Reported on
AIX 6.1

SF 5.1
SF5.1 SP1
SF 6.0